Label-Free Live-Cell Imaging of Internalized Microplastics and Cytoplasmic Organelles with Multicolor CARS Microscopy.

As the bioaccumulation of microplastics (MPs) is considered as a potential health risk, many efforts have been made to understand the cellular dynamics and cytotoxicity of MPs. Here, we demonstrate that label-free multicolor coherent anti-Stokes Raman scattering (CARS) microscopy enables separate vibrational imaging of internalized MPs and lipid droplets (LDs) with indistinguishable shapes and sizes in live cells. By simultaneously obtaining polystyrene (PS)- and lipid-specific CARS images at two very different frequencies, 1000 and 2850 cm-1, respectively, we successfully identify the local distribution of ingested PS beads and native LDs in Caenorhabditis elegans. We further show that the movements of PS beads and LDs in live cells can be separately tracked in real time, which allows us to characterize their individual intracellular dynamics. We thus anticipate that our multicolor CARS imaging method could be of great use to investigate the cellular transport and cytotoxicity of MPs without additional efforts for pre-labeling to MPs.

Compound heterozygous mutations of SH3TC2 in Charcot-Marie-Tooth disease type 4C patients.

Charcot-Marie-Tooth disease type 4C (CMT4C) is an autosomal recessive neuropathy caused by SH3TC2 mutations, characterized by spine deformities and cranial nerve involvement. This study identified four CMT4C families with compound heterozygous SH3TC2 mutations from 504 Korean demyelinating or intermediate CMT patients. The frequency of the CMT4C was calculated as 0.79% in demyelinating and intermediate patients (n = 504), but it was calculated as 2.02% in patients without PMP22 duplication (n = 198). The CMT4C frequency was similar to patients in Japan, but it was relatively low compared to those patients in other populations. The symptom was less severe and slowly progressed compared to the other AR-CMT. A patient harboring an intermediate neuropathy showed cranial nerve involvement but did not have scoliosis. This study will be helpful in making molecular diagnoses of demyelinating or intermediate CMT due to SH3TC2 mutations.

Long-term Follow-up Results of Femoral Revision Hip Arthroplasty Using Impaction Bone Grafting and Standard Cemented Polished Stem.

Background: To report the long-term clinical and radiologic results of impaction bone grafting and standard cemented polished stem for femoral revision arthroplasty in patients with extensive bone deficiency. Methods: We retrospectively reviewed 47 hips that underwent femoral revision hip arthroplasty using an impaction-morselized allograft with a standard cemented polished stem. The average age at the time of revision hip arthroplasty was 55 years (range, 39-75 years). The modified Harris hip score (HHS) was used for clinical evaluation. The radiologic evaluation focused on stem subsidence, stem position, progressive radiolucent lines, bone remodeling, and the incorporation of allografts. Results: The modified HHS improved from an average of 55.04 (range, 25-79.5) preoperatively to 90.1 (range, 81-93.2) at the last follow-up. The mean follow-up duration was 13.5 years (10.9-17.8 years). The radiographic analysis revealed stable stems. Femoral stems showed an average subsidence of 3.2 mm (range, 2-8 mm) in the cement mantle. However, there was no mechanical failure or subsidence of the cement mantle in the femurs. The stem position was neutral or varus less than 5°. No progressive radiolucent line or osteolysis was observed. Evidence of cortical and trabecular remodeling was observed in all cases. There were four cases of intraoperative cracks and four cases of distal femur splitting. Conclusions: Initial stem stability using impaction bone grafting and a standard cemented polished stem in femoral revision arthroplasty resulted in good outcome. Delicate impaction grafting techniques and intraoperative crack and splitting fixation are the points that need attention for successful long-term results.

Survival analysis and risk factors of new vertebral fracture after vertebroplasty for osteoporotic vertebral compression fracture.

BACKGROUND CONTEXT: Although risk factors of new adjacent vertebral fracture (AVF) and remote vertebral fracture (RVF) after vertebroplasty may differ, research on this topic is lacking. PURPOSE: To determine the natural course of new vertebral fractures after vertebroplasty for osteoporotic vertebral compression fracture (OVCF) and to analyze each risk factor for understanding the incidence of AVF and RVF. STUDY DESIGN: Retrospective cohort study. PATIENT SAMPLE: The study subjects included 205 patients who received vertebroplasty for OVCF and were followed-up for at least 1-year. OUTCOME MEASURES: Data on factors that could affect the occurrence of vertebral fractures, such as age, body mass index, and bone density, were collected from the patients' medical records. Fracture pattern, fracture location, sagittal imbalance, degree of segmental kyphosis after vertebroplasty, cement distribution, and cement leakage were radiologically examined. METHODS: xDuring the follow-up period, any newly developed vertebral fractures were identified. We analyzed whether the time of occurrence differed between AVF and RVF by performing a survival analysis and each risk factor separately. RESULTS: New vertebral fractures occurred in 47 patients (22.9%) after vertebroplasty, AVF occurred in 21 patients (10.2%), and RVF occurred in 26 patients (12.7%). The onset time of AVF was 6.2±1.8 months after vertebroplasty, showing a significant difference from that of RVF, which was 15.2±1.8 months (p<.001). In the univariate analysis, the risk factors of AVF included severe osteoporosis (T-score<-3.0), vertebroplasty in the thoracolumbar junction, sagittal imbalance, and segmental kyphosis angle >15° (p=0.029, p=0.033, p=0.001, and p=0.021, respectively). The risk factors of RVF included severe osteoporosis (T-score <-3.0) and sagittal imbalance (p=0.013 and p=0.004). In the multivariate analysis, the risk factors of AVF included vertebroplasty in the thoracolumbar junction and sagittal imbalance (hazard ratio=3.34, p=0.032 and hazard ratio=4.05, p=0.008), and those of RVF included only sagittal imbalance (hazard ratio=2.66, p=0.024). CONCLUSON: After vertebroplasty for OVCF, a significant difference in the meantime of occurrence was found; it took 6 months for AVF and 15 months for RVF to develop. Vertebroplasty in the thoracolumbar junction was identified as a risk factor for AVF, whereas sagittal imbalance was a risk factor of both AVF and RVF.

Placement of implant after bone graft using J block allograft.

Securing sufficient alveolar bone is important for a successful implant. Alveolar bone should be augmented to adequate height and width for an implant to satisfy the functional, biological, and aesthetic properties. The subjects of this study were 3 patients with severe bone defects caused by either a periodontal disease or a failure of implants on mandibular posterior tooth, mandibular anterior tooth, and maxillary posterior tooth. The shape of the commercial block allograft (Puros J-Block, Zimmer Dental Inc., Carlsbad, CA) was modified to match the shape of the defect, and resorbable membrane (Puros Pericardium Allograft Membrane, Tutogen Medical GmbH, Germany) was used before suturing the soft tissue. The transplant sites were exposed 4 months later to install the implant. The grafted bone was united with the bone tissue to obtain enough alveolar ridge and to install the implants. Bone allograft used in these cases reduced the need to collect autogenous bone in patients with severe alveolar ridge loss.

Developing palatal bone using human mesenchymal stem cell and stem cells from exfoliated deciduous teeth cell sheets.

Cleft palate is one of the most common craniofacial defects in newborn babies. The characteristics of this genetic disease produce soft and hard tissue defects on the lip and maxilla, which cause not only aesthetic but also functional problems with speech, eating, and breathing. Bone grafts using autologous cancellous bone have been a standard treatment to repair the hard tissue defect in cleft palates. However, such grafts do not fully integrate into host bone and undergo resorption. To overcome engraftment problems, it is common to engineer new tissues with a combination of multipotent cells and biomaterial frameworks. Here, we manufactured cell sheets for bone repair of cleft palates derived from two osteogenic cell sources, human mesenchymal stem cells (hMSCs) and stem cells from human exfoliated deciduous teeth (SHEDs). Cell sheets made from hMSCs and SHEDs gave rise to in vitro calcification, which indicated the osteogenic potential of these cells. The cell sheets of hMSCs and SHEDs expressed the bone-specific osteogenic markers, osterix, osteocalcin, and osteopontin, following insertion into ex vivo-cultured embryonic palatal shelves and in ovo culture. In conclusion, we showed that osteogenic stem cell sheets have mineralization potential and might represent a new alternative to autologous bone transplantation in the reconstruction of cleft palates.

Pentraxin 3 Modulates the Inflammatory Response in Human Dental Pulp Cells.

INTRODUCTION: Pentraxin 3 (PTX3) has been suggested as a novel inflammatory biomarker in inflammation-associated diseases. The aim of this study was to examine the role of PTX3 in the inflammatory response of human dental pulp cells (HDPCs). METHODS: HDPCs were treated with tumor necrosis factor alpha (TNF-α), and total RNA and protein were extracted. PTX3 messenger RNA and protein expression levels were analyzed using reverse transcription polymerase chain reaction and Western blotting, respectively. For PTX3 knockdown, HDPCs were transfected with a small interfering RNA against human PTX3. Macrophage chemotaxis after PTX3 silencing in HDPCs was assessed by transwell migration assays. RESULTS: TNF-α increased PTX3 messenger RNA and protein levels in HDPCs. TNF-α-induced PTX3 expression was mediated by extracellular signal-regulated kinase 1/2 and nuclear factor kappa B. PTX3 knockdown decreased the expression levels of interleukin 6, interleukin 8, and monocyte chemoattractant protein 1 after stimulation with TNF-α in HDPCs. Moreover, PTX3 silencing in HDPCs significantly decreased the chemotactic migration of macrophages. CONCLUSIONS: Our findings indicate PTX3 plays a critical role in the regulation of pulp inflammatory processes and reveal its underlying molecular mechanism.

Effect of hyaluronic acid-carboxymethylcellulose solution on perineural scar formation after sciatic nerve repair in rats.

BACKGROUND: Scar tissue formation is the major cause of failure in peripheral nerve surgery. Use of a hyaluronic acid-carboxymethylcellulose (HA-CMC) membrane (Seprafilm) as a solid anti-adhesion barrier agent is one of the therapeutic approaches to reduce postoperative scar tissue formation. However, a solid membrane may not be suitable for repair of a weak peripheral nerve site. This study examined the effect of HA-CMC solution on perineural scar formation after peripheral nerve repair in rats. METHODS: The sciatic nerves of 40 rats were transected and then immediately repaired using 10-0 nylon. The nerves were divided randomly into two groups. Saline and HA-CMC solution were applied topically to the nerve repair sites in the control and experimental groups, respectively. Reoperation was performed at 3, 6, 9, and 12 weeks to assess scar tissue formation. The assessment included the quality of wound healing, presence of perinueral adhesion, cellular components of the scar tissue, thickness of the scar tissue and histomorphological organization of the repair site. RESULTS: Topical application of the HA-CMC solution significantly decreased the macroscopic nerve adherence score and the numbers of the cellular components such as fibroblasts and inflammatory cells (p < 0.05, Mann-Whitney U-test). The scar tissue formation index was significantly lower in the experimental group at 12 weeks than that in the control group (p < 0.05, Mann-Whitney U-test). The grading scores of the histomorphological axonal organization at the repair site were significantly higher in the experimental group than those in the control group at 12 weeks (p < 0.05, Mann-Whitney U-test). No evidence of wound dehiscence or inflammatory reactions against the HA-CMC solution was noted. CONCLUSIONS: Topical application of a HA-CMC solution is effective in reducing the perineural scar formation and adhesion after sciatic nerve repair in rats, and is effective in promoting peripheral nerve regeneration at the repair site.